In recent years, the popularity of the combat game known as “Paintball” has increased dramatically. Paintball is now a recognized and popular sporting activity. In one form of this game, players on two teams are each supplied with a paintball marker (paintball gun) and a number of marking projectiles, or “paintballs,” which are rounds of ammunition. The terms “projectile” and “marking projectile” are used interchangeably. The projectiles comprise a spherical gelatin or starch shell filled with a non-toxic, water-soluble, biodegradable paint (referred to herein “liquid dye”). Paintball markers fire these paintballs using compressed gas (e.g. C02, N2, etc.) as a propellant. When a player is hit with a paintball, the paintball ruptures, “painting” or “marking” the target providing dramatic evidence of the hit, without injuring the player.
Soft and hard capsules, shells or casings have been used in the sports and leisure fields, as well as in law enforcement and military training, with liquid dye formulations within projectiles adapted to rupture upon impact with an intended target. Generally, such projectiles have the physical properties in which the casing is hard and impact resistant enough to survive normal loading and firing forces, while at the same time adapted to rupture and release the liquid dye composition upon high velocity contact with a target surface. Thus, known marking projectiles are essentially a capsule or shell filled with a liquid. The capsule or shell defines the shape of the projectile, and the fill material, which is a liquid or semi-solid, is shapeless or amorphous, and moves within the capsule or shell.
Some currently available liquid dye compositions used in paint balls contain a dye in conjunction with hydrophilic carriers containing a mixture of high and low molecular weight polyethylene glycols (PEG). Among the disadvantages associated with currently available dye compositions include tenacious or permanent staining of target fabrics, freezing and solidification of the dye composition during exposure to colder temperatures, separation and precipitation of dye composition ingredients during storage, and a thin consistency. Various liquid dyes are discussed in U.S. Pat. No. 6,530,962, which is incorporated by reference.
A marking projectile impacts a target at a high velocity, which produces an impact force upon the projectile. Projectiles are formed so that the shells do not rupture until a sufficient impact force is imparted.
Currently available projectiles formed from gelatin or starch shells and filled with marking liquid dye suffer various deficiencies, both in manufacture, and in use. These types of paintballs are expensive to manufacture, and may suffer breakage problems. Known projectile filled with liquid dye also suffer from accuracy problems, as the liquid dye tends to shift during flight.
While gelatin capsule or starch shell production may be expensive and time consuming, there currently exists an abundance of agricultural biomass, which may be defined as the biodegradable fraction of products, waste and residues from agriculture, or as plant material processing waste. Various types of biomass are discussed in U.S. Pat. No. 5,171,592, which is incorporated herein by reference. In particular, there is an abundance of cellulosic fibrous material produced as a waste byproduct of agriculture. For example, rice straw is produced throughout the world as a byproduct of rice cultivation. The options for the disposition of rice straw are limited by the great bulk of material, slow degradation in the soil, harboring of rice stem diseases, and high mineral content. Fields must be cleared of rice straw to make way for the next crop. Accordingly, alternate uses are sought for rice straw and other biomass.
Many pigments, powders, emulsifiers and binders are also freely available and inexpensive, and used in many industries. Powders are useful for their absorbent properties and their compactibility, and pigments are useful for their colorant properties.
There exists a need for improved technology relating to marking projectiles.
In particular, there is a need to improve the attributes of projectiles, by providing a projectile that is efficient to manufacture, low cost, and safe to the environment.
There is yet a further need for a projectile that is formed other than as a liquid filled capsule.
In addition, there exists the need for a paintball formed from freely available materials that may be acquired and processed at low cost.